Axially Protruding Air Guide Element for Combustion Nozzle Soot Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing combustion chamber nozzles often result in excessive fuel evaporation near the nozzle outlet, leading to fuel-rich zones and undesirable soot emissions due to inadequate dispersion and distribution of liquid fuel.
Innovation Solution
A nozzle design with a radially outer air duct and a strategically positioned air guiding element, where the air guiding element protrudes beyond the fuel duct's outflow edge by a defined length, ensuring a maximum outflow angle of less than 50°, allowing air to flow radially inward and mix more evenly with fuel, thereby improving fuel distribution and reducing soot emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional nozzle design with multiple air guide channels is used, then the structure is simple and easy to manufacture, but excessive fuel evaporates near the end of the fuel channel creating fuel-rich zones and soot emissions
Solution Approach 1:
The nozzle is divided into multiple functional zones with different air guide channels (inner, middle, outer) and fuel guide channels positioned at different radial locations. This segmentation allows different regions of the fuel-air mixture to be controlled independently, preventing fuel-rich zones and soot formation while maintaining manufacturing feasibility through modular channel design.
Solution Approach 2:
Different air guide channels provide different air flow characteristics at different radial positions. The inner air guide channel provides primary mixing, while the outer air guide channel with its specific air guide element provides localized air flow control at the periphery. This local quality differentiation ensures proper fuel distribution and prevents soot emissions without requiring complete redesign of the entire nozzle structure.
2Object-generated harmful factors
If the air guide element is positioned to improve fuel dispersion, then soot emissions are reduced, but the device complexity increases
Solution Approach 1:
The air guide element is integrated directly into the outer air guide channel structure, merging the air guiding function with the existing channel geometry. This combination achieves improved fuel dispersion and reduced soot emissions without adding separate complex components, as the air guide element forms part of the channel's inherent structure rather than a distinct auxiliary device.
Solution Approach 2:
The air guide element extends in the axial direction beyond the outflow edge of the fuel duct, creating a three-dimensional flow control structure. This axial projection allows the element to influence the air flow path and fuel distribution in a way that simple planar channel designs cannot achieve, improving dispersion without requiring multiple separate components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enhances the dispersion and distribution of the fuel-air mixture, reducing soot emissions by ensuring the fuel follows the air flow path more effectively, resulting in a more even distribution and improved combustion efficiency.
Implementation Method 1
Such an air guide element deflects the typically swirled air flowing from the further air duct radially inwards to achieve mixing with the fuel from the fuel duct and the additional air
Implementation Method 2
to achieve mixing with the fuel from the fuel duct and the additional air, particularly from the first, inner air duct. This is intended to generate a spray cloud with a fuel-air mixture in which the fuel is present in finely dispersed droplets
Implementation Method 3
The air guide element projects forward of this outflow edge – with a defined length – in an axial direction relative to the nozzle's longitudinal axis, such that a reference angle that exists between the nozzle longitudinal axis and a boundary line passing through a (first) point at the outflow edge and tangential to the axially projecting air guide element less than or equal to 50°
Implementation Method 4
This allows the fuel to better follow the airflow path, which, in the case of multiple (at least two) radially outward-facing air guide channels, flows out of the outermost radial air guide channel. This results in the droplet-shaped fuel being directed more radially outwards and mixed more thoroughly with the air
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
The present invention relates to a combustion chamber assembly, comprising a burner seal (4) which has a bearing section (41) extending along a nozzle longitudinal axis (DM) with a through-opening and with a nozzle positioned in the through-opening of the bearing section (41) for a combustion chamber (3) of an engine (T) for providing a fuel-air mixture at a nozzle outlet opening of the nozzle (2).According to the invention, one end of a fuel guide channel (25) at a nozzle outlet opening of the nozzle is bounded by a radially outer discharge edge (250), and an air guide element (271b) of a radially outer air guide channel (27b) of the nozzle (2) projects in the axial direction (x) relative to this discharge edge (250) such that: - a reference angle (a) exists between the nozzle longitudinal axis (DM) and a boundary line (6) passing through a point on the discharge edge (250) and tangentially to the axially projecting air guide element (271b), and/or - a reference angle (a) exists between the nozzle longitudinal axis (DM) and a boundary line (6) passing through a point on the discharge edge (250) and a point projecting maximally in the axial direction (x) beyond the discharge edge (250). (2712b) of the air guide element (271b) runs at an angle less than or equal to 50°.The burner seal (4) further comprises a radially expanding flow-guiding element (40) in the region of the nozzle outlet opening of the nozzle (2). An inner surface of the radially expanding flow-guiding element (40) extends at the end of the burner seal (4) at an angle to the nozzle longitudinal axis (DM) which essentially corresponds to or is identical with the reference angle (a).